+

WO1993008674A1 - Filtre de protection contre les interferences electromagnetiques - Google Patents

Filtre de protection contre les interferences electromagnetiques Download PDF

Info

Publication number
WO1993008674A1
WO1993008674A1 PCT/US1992/001113 US9201113W WO9308674A1 WO 1993008674 A1 WO1993008674 A1 WO 1993008674A1 US 9201113 W US9201113 W US 9201113W WO 9308674 A1 WO9308674 A1 WO 9308674A1
Authority
WO
WIPO (PCT)
Prior art keywords
porous
electrically
composite material
conductive material
metallized
Prior art date
Application number
PCT/US1992/001113
Other languages
English (en)
Inventor
Fred G. Hedrick
Craig D. Lack
Original Assignee
W.L. Gore & Associates, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by W.L. Gore & Associates, Inc. filed Critical W.L. Gore & Associates, Inc.
Priority to AU22448/92A priority Critical patent/AU661855B2/en
Priority to DE69211009T priority patent/DE69211009T2/de
Priority to JP50765093A priority patent/JP2869189B2/ja
Priority to EP19920914411 priority patent/EP0609223B1/fr
Publication of WO1993008674A1 publication Critical patent/WO1993008674A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/12—Layered products comprising a layer of synthetic resin next to a fibrous or filamentary layer
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/18—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by features of a layer of foamed material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/02—Layer formed of wires, e.g. mesh
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B15/08—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
    • B32B27/322—Layered products comprising a layer of synthetic resin comprising polyolefins comprising halogenated polyolefins, e.g. PTFE
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
    • B32B5/022—Non-woven fabric
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0007—Casings
    • H05K9/0041—Ventilation panels having provisions for screening
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • H05K9/0084—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising a single continuous metallic layer on an electrically insulating supporting structure, e.g. metal foil, film, plating coating, electro-deposition, vapour-deposition
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • H05K9/009—Electromagnetic shielding materials, e.g. EMI, RFI shielding comprising electro-conductive fibres, e.g. metal fibres, carbon fibres, metallised textile fibres, electro-conductive mesh, woven, non-woven mat, fleece, cross-linked
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2262/00—Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
    • B32B2262/02—Synthetic macromolecular fibres
    • B32B2262/0276—Polyester fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2305/00—Condition, form or state of the layers or laminate
    • B32B2305/38—Meshes, lattices or nets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
    • B32B2307/202—Conductive
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2307/00—Properties of the layers or laminate
    • B32B2307/20—Properties of the layers or laminate having particular electrical or magnetic properties, e.g. piezoelectric
    • B32B2307/212—Electromagnetic interference shielding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2327/00—Polyvinylhalogenides
    • B32B2327/12—Polyvinylhalogenides containing fluorine
    • B32B2327/18—PTFE, i.e. polytetrafluoroethylene
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249955—Void-containing component partially impregnated with adjacent component
    • Y10T428/249956—Void-containing component is inorganic
    • Y10T428/249957—Inorganic impregnant
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249955—Void-containing component partially impregnated with adjacent component
    • Y10T428/249958—Void-containing component is synthetic resin or natural rubbers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/3154—Of fluorinated addition polymer from unsaturated monomers
    • Y10T428/31544—Addition polymer is perhalogenated

Definitions

  • This invention relates to electromagnetic radiation shielding materials and, more particularly, to porous , oleophobic, hydrophobic, chemical- and gas-resistant materials having high electromagnetic radiation shielding characteristics and high particle filtration performance for use in electronic equipment enclosures.
  • shielded electronic equipment enclosures and housings provide internal ventilation, temperature control and ambient pressure equilibration by air circulation through them.
  • Air passage into the enclosures is through electromagnetic radiation shielding devices and air filters located in the enclosure vents. It is expected of these shielding devices and filters that they prevent, or reduce to acceptable levels, passage of electromagnetic radiation or interference (EMI); and that they also prevent passage of particulate materials, to specified size levels; while minimizing impediments to flow of air through the enclosure.
  • EMI electromagnetic radiation or interference
  • metal honeycomb assemblies are very effective in shielding against EMI, however, they are quite bulky, ranging in thickness from about 1/2" to several inches depending on the electromagnetic radiation frequency range over which they are providing shielding.
  • honeycomb assemblies are usually arrays of open tubes that provide no barrier properties to passage of dust, dirt, or other particles through them and, consequently, require that separate filtration units be included in the equipment if prevention of passage of particles into the enclosure is important.
  • separate filtration units be included in the equipment if prevention of passage of particles into the enclosure is important.
  • TIT E HEET effective EMI-shielding filter assemblies can be constructed from methods and materials well known in the art.
  • This invention provides a lightweight porous material that has high electromagnetic radiation shielding properties; excellent barrier properties to fine liquid and solid particulates; high resistance to wetting and penetration by water and oils; high resistance to attack or damage by chemicals; and excellent air flow characteristics. Combination of the preceding stated properties in a single material has been heretofore unknown.
  • the material of the invention can be readily fabricated by conventional means to form compact, space- and weight-saving air vent filters for electronic equipment that protect the equipment from adverse influence or damage by electromagnetic radiation or intrusion by airborne particles, and which can be used in almost any indoor or outdoor environment without loss of effectiveness.
  • the material of the invention is a porous composite material comprising a porous electrically-conductive material to which is adhered a porous hydrophobic material or a porous oleophobic material.
  • Figure 1 illustrates embodiments having a layer of porous electrically- conductive material laminated to an outer protective layer of porous hydrophobic material (Figure la) or of porous oleophobic material (Figure lb).
  • Figure 2 illustrates embodiments having a porous protective layer laminated to each side of a porous electrically-conductive layer.
  • the porous outer protective layer of one embodiment is a porous hydrophobic material ( Figure 2a) and in the other embodiment the porous outer protective layer is a porous oleophobic material ( Figure lb).
  • Figure 3 illustrates another embodiment of the invention, having a single layer, of porous electrically-conductive material which has been coated with an oleophobic material.
  • Porous is used herein to describe materials that allow passage of gases, especially air. These are materials that comprise interconnected pores and voids that form passages extending through the thickness of the material. The passageways open on both sides of the material.
  • Figures la and lb are exploded cross-section views of two- layer embodiments of the invention.
  • Figures 2a and 2b are exploded cross-section views of three- layer embodiments of the invention.
  • two-layer embodiments of the invention comprise a porous layer of electrically conductive material 2 adhered to a porous outer protective layer of porous hydrophobic material 5 or porous oleophobic coated material 15 by a porous layer of adhesive 3.
  • the electrically conductive material 2 may be any porous material having sufficient electrical conductivity and having a structure such that incident electromagnetic radiation presented to it will be substantially reflected, intercepted, or otherwise attenuated.
  • Such electrically conductive materials include woven wire mesh, sintered porous metals, metal sponges, etc.
  • Another electrically-conductive material is film or sheet of porous expanded polytetrafluoroethylene containing electrically-conductive
  • T TE SHEET particles Such a particle-filled sheet or film can be prepared by coagulation of a mixture of electrically-conductive particles and polytetrafluoroethylene particles suspended in an aqueous dispersion and processing the mixture into a porous expanded form as described in U.S.Patents Nos. 3,953,566 and 4,187,390.
  • Suitable electrically-conductive filler particles include metal particles such as silver, gold, nickel, stainless steels, and the like or, preferably, high conductivity carbon particles.
  • the materials most preferred for the electrically-conductive layer 2 are porous non-woven sheet or film of synthetic polymers.
  • porous non-woven sheet or film may be prepared from the classes of polymers including, but not limited to, polyamides, polyesters, polyolefins, polyurethanes, fluoropolymers, and the li e, by fiber processes known in the art such as spin bonding, felting, paper-making, and the like, or by other pore-forming processes known in the art, for example, foaming, stretching, or expansion processes.
  • the non-woven sheet or film are made electrically conductive by application of metals to their surfaces by metallizing processes such as vapor deposition, sputter coating, and the like, or preferably, by electroless chemical deposition processes.
  • U.S. Patent Nos. 4,557,957 and 4,720,400 describe electroless chemical plating methods suitable for metallizing internal pore surfaces as well as external surfaces of porous expanded polytetrafluoroethylene. The methods described can also be used to plate other porous synthetic polymer film and sheet which, although not as inherently hydrophobic as polytetrafluoroethylene, are substantially resistant to penetration of water and aqueous chemical solutions.
  • porous outer protective layer of porous hydrophobic material 5 or porous oleophobic coated material 15 forms the outermost layer of the layered material of the invention, serving as a barrier to passage of liquid and solid particulates in the local environment while allowing passage of gases through it, for example, into or out of an equipment enclosure for cooling purposes or pressure equilibration.
  • the porous hydrophobic outer protective layer 5 can be any material having suitable air flow and filtration characteristics and which is inherently hydrophobic or oleophobic or, which can be treated to develop hydrophobic and/or oleophobic properties in it.
  • the material can be a fabric, such as a non-woven, woven, or knit fabric.
  • the material can be made as a paper, for example, a synthetic or natural filter paper or cloth.
  • the material can also be a porous film or membrane of synthetic polymers including polya ides, polyesters, polyolefins such as polyethylene or polypropylene, polyacrylics, polyvinylidene fluoride, and the like.
  • porous polytetrafluoroethylene most preferably, porous expanded polytetrafluoroethylene membrane or film made as described in U.S. Patent No. 3,953.566, which has a porous microstructure of nodes interconnected by fibrils.
  • the resulting pores or voids allow for good gas or air flow, provide excellent particle filtration properties, and, due to the high inherent hydrophobicity of polytetrafluoroethylene, resistance to penetration of liquid water or aqueous solutions.
  • the porous expanded polytetrafluoroethylene membrane or film imparts excellent chemical resistance and broad temperature range of use to the material of the invention due to the chemical inertness and thermal properties of polytetrafluoroethylene.
  • porous expanded polytetrafluoroethylene and other porous gas permeable materials described above can be coated with an amorphous copoiymer of tetrafluoroethylene and perfluoro-2,2- dimethyl-l,3-dioxole to significantly enhance their hydrophobic properties and to develop oleophobic properties in them.
  • the copoiymer is available from the DuPont Company as Teflon (R) AF 1600 in which the dioxole concentration is about 65 mole percent, and as Teflon (R) AF 2400 in which the dioxole concentration is about 85 mole percent.
  • the oleophobic copoiymer coating is applied from a dilute solution, for example, a solution of perfluoro-(2- butyltetrahydrofuran) solvent (also known as Fluoroinert-75, or FC- 75, from Dow Chemical Co.) containing copoiymer solids in the concentration range 0.01 to 5.0 wt. percent.
  • a dilute solution for example, a solution of perfluoro-(2- butyltetrahydrofuran) solvent (also known as Fluoroinert-75, or FC- 75, from Dow Chemical Co.) containing copoiymer solids in the concentration range 0.01 to 5.0 wt. percent.
  • FC- 75 Fluoroinert-75
  • the solution can be applied to the porous permeable materials by conventional means such as spraying, transfer roll coating, dip coating, brushing, and the like, after which the solvent is dried by any convenient means.
  • the coating coats all the outside surfaces and at least a portion of the interior surfaces of the pores without blocking the pores or excessively reducing the void volume of the porous material to which it is applied.
  • the adhesive of the porous layer of adhesive 3 may be selected from many well known in the art.
  • the adhesives can be thermopl stic, thermosetting, or reaction curing types, in liquid or solid form, selected from the classes including, but not limited to, polyamides, polyacrylamides, polyesters, polyolefins, polyurethanes, and the like.
  • the adhesive must be applied so that it forms a porous gas permeable layer which minimizes resistance to air flow while adhering the porous outer protective layer 5 to the porous electrically-conductive layer 2. Suitable application means include gravure printing, spray coating, powder coating, and the like.
  • a preferred adhesive is a thermoplastic polymer in the form of a non-woven web or mesh.
  • the non-woven thermoplastic web or mesh is placed between the porous electrically-conductive layer 2 and the porous hydrophobic or oleophobic outer protective layer 5 and, by applying heat and pressure, for example, by a hot-roll and a pinch- roll or by a heated press, the thermoplastic adhesive web is melted and the porous electrically-conductive material layer 2 is adhered to the porous hydrophobic or oleophobic material of the outer protective layer 5, thus forming the porous layered material of the invention.
  • electroless chemical plating for process and cost considerations it may be desirable to alter the order in which the electroless chemical plating, oleophobic coating, and/or lamination take place.
  • electroless chemical plating of a porous material laminated to an oleophobic outer protective layer can be done after lamination without difficulty and without loss of function.
  • oleophobic coatings can be applied to single layers or laminated constructions equally well.
  • porous composite material of the invention which comprises a single layer 12 of porous electrically- conductive material coated with the amorphous copoiymer of tetrafluoroethylene and perfluoro-2,2-dimethyl-l,3-dioxole can be used.
  • the porous electrically-conductive material selected from the classes and prepared as described above, provides the same level of EMI shielding as in the laminated form and, when coated with the amorphous copoiymer of tetrafluoroethylene and perfluoro - 2,2-dimethyl-l,3-dioxole as described above, exhibits good hydrophobic and oleophobic properties while having good gas or air flow through the material.
  • FIG. 2 Three-layer embodiments of the invention are shown in Figure 2. These embodiments comprise a porous layer of electrically- conductive material 2 adhered to a porous outer protective layer of porous hydrophobic material 5 or porous oleophobic coated material 15 by a porous layer of adhesive 3, all as specified above in the description of the broadest embodiment of the invention. It further comprises a porous inner protective layer 6 adhered to the inside surface of the electrically-conductive layer 2 by a porous layer of adhesive 4. The porous inner protective layer 6 prevents contact with the porous electrically-conductive material layer 2, thus reducing the likelihood of damage to the porous electrically- conductive layer during assembly, handling, and use. The porous inner protective material layer 6 provides further protection by preventing migration of any particles that may be shed by the porous electrically-conductive material layer 2.
  • the porous inner protective material layer 6 can be of any material having suitable airflow and filtration characteristics and also having excellent non-1inting or non-shedding characteristics.
  • the material can be a fabric or paper as described above with respect to the material of the porous outer protective layer, however, more preferable materials are porous films, membranes, non-woven webs and meshes of synthetic polymers also described above.
  • Porous polytetrafluoroethylene preferably porous expanded polytetrafluoroethylene membrane or film made as described in U.S. Patent No. 3,953,566 is most preferred as the material for the porous inner protective layer 6.
  • the porous expanded polytetrafluoroethylene membrane or film has especially good non-linting and non-shedding characteristics.
  • BSTITUTE SHEET Selection, application, and processing of the material of the porous layer of adhesive 4 is as described above with respect to the porous layer of adhesive 3, however, referring to Figure 2, the materials forming the porous layers of adhesive 3, 4 may be, but are not necessarily, the same. It may be desirable, for process considerations, to use a different material in each porous layer of adhesive, for example, a different adhesive polymer in each layer or an adhesive polymer type having a different melt point in each layer *
  • Gurley densometer manufactured by W. & L.E. Gurley & Sons
  • Test Standard ASTM D726-58 The results are reported in terms of Gurley-number (also Gurley-seconds) which is the time in seconds for 100 cubic centimeters of air to pass through 1 square inch of a test sample at a pressure drop of 4.88 inches of water.
  • test liquids are a series of eight liquid hydrocarbons of different surface tensions, small drops of which are placed on the sample surface and observed for wetting.
  • Oil Repellency Rating is the highest numbered test liquid which does not wet the test surface. Testing was done according to the test method except that samples smaller than 8 in. x 8 in. were used and the samples were not necessarily conditioned as specified prior to testing.
  • EMI Shielding Effectiveness of test samples was measured according to ASTM Standard Test Method D4935-89 for measuring the Electromagnetic Shielding Effectiveness of Planar Materials; modified for use in measuring in the frequency range 1 to 18 Gigaherz (GHz).
  • SE Shielding Effectiveness
  • a layered porous material of the invention having a hydrophobic outer protective layer was prepared as follows:
  • a first porous expanded polytetrafluoroethylene membrane was made electrically-conductive by electroless chemical plating the membrane with a first layer of copper and a second layer of nickel by the methods set forth in U.S.Patent Nos. 4,557,957 and 4,720,400. Properties of the membrane before and after plating are tabulated below.
  • a second porous expanded polytetrafluoroethylene membrane, approximately 0.003 inches thick, and the electrically-conductive membrane were laminated together by interposing a layer of Sharnet 4200 (non-woven polyester adhesive web, manufactured by Applied Extrusion Technologies, Inc.) between them and applying heat and pressure to the assembly by passing the assembly through the nip of a hot-roll and a pinch-roll.
  • Sharnet 4200 non-woven polyester adhesive web, manufactured by Applied Extrusion Technologies, Inc.
  • SUBSTITUTE SHEET found to have Air Permeability of 5.6 Gurley-seconds and EMI Shielding Effectiveness of -70 decibels.
  • a layered porous material of the invention having a hydrophobic outer protective layer was prepared as follows:
  • a spun-bonded polyester fiber web (Reemay #2033, manufactured by Reemay, Inc.), approximately 0.020 inches thick, was made electrically-conductive by electroless chemical plating the web with a first layer of copper and a second layer of nickel as described in Example 1 above. Properties of the Reemay 2033 web before and after plating are tabulated below.
  • the electrically-conductive Reemay 2033 polyester fiber web was laminated to a section of the 0.003 inch thick porous expanded polytetrafluoroethylene membrane described above using the materials and methods also described in Example 1 above.
  • the finished layered material of the invention was tested and found to have Air Permeability of 1.9 Gurley-seconds and EMI Shielding Effectiveness of -85 decibels.
  • a layered porous material of the invention having an oleophobic outer protective layer was prepared as follows:
  • a 0.003 inch thick porous expanded polytetrafluoroethylene membrane was coated with Teflon AF 1600 Amorphous Fluoropolymer to make it oleophobic.
  • the membrane was immersed in a bath containing a solution of 0.5 % Teflon AF 1600 in FC-75 solvent after which it was oven-dried to remove the solvent.
  • the membrane had an Oil Repellency Rating of 0 before coating and 6 after coating.
  • the oleophobic porous expanded polytetrafluoroethylene was laminated to a section of the electrically-conductive Reemay 2033 polyester fiber web described in Example 2 with Sharnet 4200 adhesive as described in Example 1.
  • the finished layered material of the invention was tested and was found to have Air Permeability of 36 Gurley-seconds, Oil Repellency Rating of 4, and EMI Shielding Effectiveness of -85 decibels.
  • a layered porous material of the invention having an oleophobic outer protective layer was prepared as follows:
  • Porous spun-bonded polyester fiber web (Reemay #2033) was laminated to the oleophobic porous expanded polytetrafluoroethylene membrane described in Example 3 above. Lamination of the layers was effected using Sharnet 4200 adhesive with heat and pressure applied by passing them through the nip of a hot-roll and a pinch- roll.
  • the spun-bonded polyester web layer was then selectively made electrically-conductive by electroless chemical plating it with a first layer of copper and a second layer of nickel.
  • the finished layered material of the invention was tested and found to have Air Permeability of 23 Gurley-seconds, Oil Repellency Rating of 3, and EMI Shielding Effectiveness of -75 decibels.

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Textile Engineering (AREA)
  • Dispersion Chemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Laminated Bodies (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Chemically Coating (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
  • Surgical Instruments (AREA)
  • Filtering Materials (AREA)

Abstract

Matériau composite poreux constitué par des matériaux poreux électriquement conducteurs recouverts par des matériaux poreux hydrophobes ou oléophobes, ou bien formant une structure stratifiée avec ces derniers. Ledit matériau composite poreux présente d'excellentes caractéristiques de protection contre le rayonnement électromagnétique et résiste à la pénétration de particules, tout en permettant le passage d'air ou d'autres gaz.
PCT/US1992/001113 1991-10-23 1992-02-10 Filtre de protection contre les interferences electromagnetiques WO1993008674A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
AU22448/92A AU661855B2 (en) 1991-10-23 1992-02-10 Electromagnetic interference shielding filter
DE69211009T DE69211009T2 (de) 1991-10-23 1992-02-10 Abschirmungsfilter gegen elektromagnetische interferenz
JP50765093A JP2869189B2 (ja) 1991-10-23 1992-02-10 電磁干渉遮蔽フィルタ
EP19920914411 EP0609223B1 (fr) 1991-10-23 1992-02-10 Filtre de protection contre les interferences electromagnetiques

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US78143591A 1991-10-23 1991-10-23
US781,435 1991-10-23

Publications (1)

Publication Number Publication Date
WO1993008674A1 true WO1993008674A1 (fr) 1993-04-29

Family

ID=25122731

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1992/001113 WO1993008674A1 (fr) 1991-10-23 1992-02-10 Filtre de protection contre les interferences electromagnetiques

Country Status (6)

Country Link
US (1) US5506047A (fr)
EP (1) EP0609223B1 (fr)
JP (1) JP2869189B2 (fr)
AU (1) AU661855B2 (fr)
DE (1) DE69211009T2 (fr)
WO (1) WO1993008674A1 (fr)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5488766A (en) * 1991-09-19 1996-02-06 W. L. Gore & Associates, Inc. Weather-resistant electromagnetic interference shielding for electronic equipment enclosures
WO1996006520A1 (fr) * 1994-08-19 1996-02-29 W. L. Gore & Associates, Inc. Ensemble de protection transparent contre les rayonnements
WO1997046069A1 (fr) * 1996-05-28 1997-12-04 Nellcor Puritan Bennett Incorporated Blindage emi en treillis metallique continu destine a un detecteur pour sphygmo-oxymetre
EP0856550A1 (fr) * 1997-02-03 1998-08-05 W.L. Gore & Associates, Inc. Textiles antistatiques
EP0858884A3 (fr) * 1996-12-18 1999-08-18 Japan Gore-Tex, Inc. Matériau textile antistatique
EP0804269B1 (fr) * 1994-08-22 2002-01-16 W.L. Gore & Associates, Inc. Stratifie filtrant conducteur
EP1383138A1 (fr) * 2002-07-18 2004-01-21 Hokkaido University Absorption des ondes électromagnetique
EP2154950A4 (fr) * 2007-05-16 2010-06-23 Chase Corp Matériau de protection électromagnétique
CN105493650A (zh) * 2013-08-26 2016-04-13 萨蒂公司 磁场保护和屏蔽的多层纺织品结构
US11123958B2 (en) 2014-08-25 2021-09-21 Chase Corporation Paper/plastic laminate and electromagnetic shielding material
CN117507543A (zh) * 2023-09-11 2024-02-06 苏州羽燕特种材料科技有限公司 一种tpu高阻隔复合织物的制备方法

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH101554A (ja) * 1996-06-18 1998-01-06 Nisshinbo Ind Inc 撥油性に優れたメラミン系樹脂発泡体
US5981614A (en) * 1996-09-13 1999-11-09 Adiletta; Joseph G. Hydrophobic-oleophobic fluoropolymer compositions
US5989698A (en) * 1997-02-10 1999-11-23 3M Innovative Properties Company Coated porous materials
US6063152A (en) * 1997-02-19 2000-05-16 Marconi Communications Inc. Tuned electromagnetic interference air filter
US6171357B1 (en) * 1999-01-04 2001-01-09 Eci Telecom Ltd. Air filter
US6364247B1 (en) 2000-01-31 2002-04-02 David T. Polkinghorne Pneumatic flotation device for continuous web processing and method of making the pneumatic flotation device
TWI258771B (en) 2001-12-04 2006-07-21 Laird Technologies Inc Methods and apparatus for EMI shielding
AU2003279736A1 (en) * 2002-10-03 2004-04-23 Laird Technologies, Inc. Emi-absorbing air filter
US7338547B2 (en) * 2003-10-02 2008-03-04 Laird Technologies, Inc. EMI-absorbing air filter
KR101548279B1 (ko) * 2013-12-20 2015-08-28 주식회사 불스원신소재 전자파 차폐 및 흡수용 부직포 또는 부직포 복합재
JP6278922B2 (ja) * 2015-03-30 2018-02-14 Ｊｘ金属株式会社 電磁波シールド材
US10004163B2 (en) * 2016-05-27 2018-06-19 Oracle America, Inc. Integrated environmental control for electronic equipment enclosures
JP6666477B2 (ja) * 2016-06-01 2020-03-13 インテグリス・インコーポレーテッド 流体回路及び流体回路の動作構成要素
CN110494279B (zh) 2017-04-04 2022-02-15 W.L.戈尔有限公司 具有增强弹性体和集成电极的介电复合物
US10327063B1 (en) 2018-03-23 2019-06-18 Gopro, Inc. Systems and methods for minimizing vibration sensitivity for protected microphones
MY205189A (en) 2018-05-07 2024-10-05 Entegris Inc Fluid circuit with integrated electrostatic discharge mitigation
EP3973216A4 (fr) 2019-05-23 2023-01-04 Entegris, Inc. Tube d'atténuation de décharge électrostatique

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3953566A (en) * 1970-05-21 1976-04-27 W. L. Gore & Associates, Inc. Process for producing porous products
US4255384A (en) * 1978-08-14 1981-03-10 Fuji Photo Film Co., Ltd. Multilayered integral element for the chemical analysis of the blood
EP0152632A2 (fr) * 1983-12-30 1985-08-28 Nitto Denko Corporation Film poreux électroconducteur et procédé de fabrication
US4557957A (en) * 1983-03-18 1985-12-10 W. L. Gore & Associates, Inc. Microporous metal-plated polytetrafluoroethylene articles and method of manufacture
US4720400A (en) * 1983-03-18 1988-01-19 W. L. Gore & Associates, Inc. Microporous metal-plated polytetrafluoroethylene articles and method of manufacture
EP0256756A2 (fr) * 1986-08-05 1988-02-24 Minnesota Mining And Manufacturing Company Ruban électriquement conducteur
WO1992009429A1 (fr) * 1990-11-23 1992-06-11 Chemfab Corporation Materiaux composites ameliores a usage structural architectural

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2419256A1 (fr) * 1978-03-10 1979-10-05 Rhone Poulenc Ind Procede de separation des terres rares
US5116650A (en) * 1990-12-03 1992-05-26 W. L. Gore & Associates, Inc. Dioxole/tfe copolymer composites

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3953566A (en) * 1970-05-21 1976-04-27 W. L. Gore & Associates, Inc. Process for producing porous products
US4187390A (en) * 1970-05-21 1980-02-05 W. L. Gore & Associates, Inc. Porous products and process therefor
US4255384A (en) * 1978-08-14 1981-03-10 Fuji Photo Film Co., Ltd. Multilayered integral element for the chemical analysis of the blood
US4557957A (en) * 1983-03-18 1985-12-10 W. L. Gore & Associates, Inc. Microporous metal-plated polytetrafluoroethylene articles and method of manufacture
US4720400A (en) * 1983-03-18 1988-01-19 W. L. Gore & Associates, Inc. Microporous metal-plated polytetrafluoroethylene articles and method of manufacture
EP0152632A2 (fr) * 1983-12-30 1985-08-28 Nitto Denko Corporation Film poreux électroconducteur et procédé de fabrication
EP0256756A2 (fr) * 1986-08-05 1988-02-24 Minnesota Mining And Manufacturing Company Ruban électriquement conducteur
WO1992009429A1 (fr) * 1990-11-23 1992-06-11 Chemfab Corporation Materiaux composites ameliores a usage structural architectural

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5488766A (en) * 1991-09-19 1996-02-06 W. L. Gore & Associates, Inc. Weather-resistant electromagnetic interference shielding for electronic equipment enclosures
WO1996006520A1 (fr) * 1994-08-19 1996-02-29 W. L. Gore & Associates, Inc. Ensemble de protection transparent contre les rayonnements
EP0804269B1 (fr) * 1994-08-22 2002-01-16 W.L. Gore & Associates, Inc. Stratifie filtrant conducteur
WO1997046069A1 (fr) * 1996-05-28 1997-12-04 Nellcor Puritan Bennett Incorporated Blindage emi en treillis metallique continu destine a un detecteur pour sphygmo-oxymetre
EP0858884A3 (fr) * 1996-12-18 1999-08-18 Japan Gore-Tex, Inc. Matériau textile antistatique
EP0856550A1 (fr) * 1997-02-03 1998-08-05 W.L. Gore & Associates, Inc. Textiles antistatiques
EP1383138A1 (fr) * 2002-07-18 2004-01-21 Hokkaido University Absorption des ondes électromagnetique
EP2154950A4 (fr) * 2007-05-16 2010-06-23 Chase Corp Matériau de protection électromagnétique
CN105493650A (zh) * 2013-08-26 2016-04-13 萨蒂公司 磁场保护和屏蔽的多层纺织品结构
US10045469B2 (en) 2013-08-26 2018-08-07 Saati S.P.A. Magnetic field protecting and screening multi-layer textile construction
CN105493650B (zh) * 2013-08-26 2019-01-11 萨蒂公司 磁场保护和屏蔽的多层纺织品结构
US11123958B2 (en) 2014-08-25 2021-09-21 Chase Corporation Paper/plastic laminate and electromagnetic shielding material
CN117507543A (zh) * 2023-09-11 2024-02-06 苏州羽燕特种材料科技有限公司 一种tpu高阻隔复合织物的制备方法

Also Published As

Publication number Publication date
JP2869189B2 (ja) 1999-03-10
EP0609223B1 (fr) 1996-05-22
DE69211009T2 (de) 1996-11-28
US5506047A (en) 1996-04-09
AU661855B2 (en) 1995-08-10
AU2244892A (en) 1993-05-21
DE69211009D1 (de) 1996-06-27
EP0609223A1 (fr) 1994-08-10
JPH07500456A (ja) 1995-01-12

Similar Documents

Publication Publication Date Title
EP0609223B1 (fr) Filtre de protection contre les interferences electromagnetiques
EP0604426B1 (fr) Blindage protecteur contre les interferences electromagnetiques, resistant aux intemperies, pour boitiers d'equipement electronique
EP0732042B1 (fr) Agencement de protection contre les radiations electromagnetiques
CA1224092A (fr) Articles en polytetrafluoroethylene poreux metallise, et leur fabrication
DE10053681B4 (de) Gehäuse mit mindestens einem EMI abschirmender Kunststoffkörper bzw. Be- und Entlüftungselement und Verfahren zur Herstellung eines solchen Kunststoffkörpers
EP1685740B1 (fr) Ensemble couvercle de protection
CA2202657C (fr) Stratifie filtrant conductible
US4720400A (en) Microporous metal-plated polytetrafluoroethylene articles and method of manufacture
DE19833247C2 (de) Schutzabdeckung eines Gebläsekühlaggregats
EP0477015B1 (fr) Matériaux de régulation thermique
US20080064279A1 (en) Densified conductive materials and articles made from same
US20150366107A1 (en) Panel for broadband electromagnetic shielding
US5519168A (en) Electromagnetic interference shielding
KR101370581B1 (ko) 멤브레인 어셈블리
KR101292088B1 (ko) 통기성 및 소수성을 갖는 다층 복합소재
KR101415304B1 (ko) 통기성과 소수성을 갖는 필터
WO1994005142A1 (fr) Tissu textile en fibres recouvertes de metal pour ecran electromagnetique et procede de preparation de ce tissu

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU JP

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LU MC NL SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 1992914411

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1992914411

Country of ref document: EP

WWG Wipo information: grant in national office

Ref document number: 1992914411

Country of ref document: EP

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载